The field of this invention is vascular disease, particularly vascular diseases characterized by the presence of calcified vascular occlusions.
Vascular occlusions, which may be partial or total occlusions, play a prominent role in many types of vascular disease. Many vascular occlusions encountered in the treatment of vascular disease are characterized by having a mineral component, i.e., they are calcified. Calcified vascular occlusions, both partial and total, are found in both peripheral and coronary vascular disease
A variety of different protocols have been developed for treating vascular diseases characterized by the presence of partial or total occlusions. Such treatment methodologies generally involve mechanical removal or reduction of the size of the occlusion, and include: bypass surgery, balloon angioplasty, mechanical debridement, atherectomy, and the like.
Despite the plethora of different treatment strategies that have been developed for the treatment of vascular diseases associated with vascular occlusions, there are disadvantages associated with each technique, such as tissue damage, invasiveness, etc. For example, restenosis is a common complication that results in arteries in which occlusions have been mechanically removed.
Calcified vascular occlusions pose significant challenges to currently employed treatment methodologies. For example, where the target vascular occlusion is a total occlusion, it is difficult if not impossible to pass a guidewire through the occlusion, which step is required for many of the currently used procedures. While bypass grafts are sometimes available as alternatives in such instances, bypass procedures have their own risks and complications. As such, there is continued interest in the development of endovascular methods of treating vascular occlusions. Of particular interest would be the development of methods and devices suitable for use in the treatment of calcified vascular occlusions.
Relevant Literature
U.S. patents of interest include: U.S. Pat. Nos. 4,445,892; 4,573,966; 4,610,662; 4,636,195; 4,655,746; 4,690,672; 4,824,436; 4,911,163; 4,976,733; 5,059,178; 5,090,960; 5,167,628; 5,195,955; 5,222,941; 5,370,609; 5,380,284; 5,443,446; 5,462,529; 5,496,267; 5,785,675; and 5,833,650.
Catheter devices having electrodes positioned at their distal ends include those described in U.S. Pat. Nos. 5,997,536; 5,997,532; 5,941,845; 5,938,694; 5,938,659; 5,935,124; 5,935,102; 5,935,063; 5,931,835; 5,916,163; 5,916,158; 5,897,554; 5,893,885; 5,893,884; 5,891,135; 5,879,295; 5,871,444; 5,860,974; 5,853,425; 5,848,972; 5,843,152; 5,837,001; 5,836,990; 5,836,875; 5,827,278; 5,827,272; 5,817,093; 5,814,076; 5,792,140; 5,782,898; 5,782,239; 5,779,699; 5,772,590; 5,730,704; 5,718,701; and RE 35,924.
Catheter devices and methods are provided for enhancing fluid flow through a vascular site occupied by a calcified lesion. The catheter devices of the subject invention at least include, at their distal end, a proton generating means, and in many embodiments also include a flushing means. In using the subject devices, the distal end of the catheter is placed proximal to the vascular occlusion and protons are generated, e.g., via proton generation from water, in a manner sufficient to reduce the pH of the vascular site in the region proximal to the occlusion. The sub-physiologic pH is maintained for a period of time sufficient for fluid flow through the vascular site to be enhanced. Also provided are kits that include the subject catheter devices for use in the subject methods.